In this research proposal, I outline a series of experiments aimed at utilizing multiple methodologies to examine detailed information about the spatio-temporal properties of neural networks engaged in working memory (WM) and long-term memory (LTM) processes. Understanding the nature of these fundamental mechanisms in normal individuals will shed light on the memory impairments that emerge in normal aging and following prefrontal strokes. The research outline is based on the theoretical stance that the PFC participates in a diverse set of mnemonic control processes by sending top-down modulatory signals to posterior networks. In these experiments, I will focus specifically on two questions about these neural networks: 1.) What are the subregions of the PFC that interact with posterior perceptual regions during the encoding and retrieval of representations from WM? 2.) What are the temporal dynamics of these networks and how do they illuminate the role of the PFC in top- down control processes? Particular emphasis is placed on appreciating the role of discrete subregions of the PFC in mnemonic operations and how their interactions with posterior brain networks dynamically change across cognitive operations. [unreadable] [unreadable] [unreadable]